It is a long time since my last v4 [1]. The code has undergone great changes. The paca[] array has been reorganized and indexed by paca_ptrs[], which dramatically decreases the memory consumption even if there are many unpresent cpus in the middle.
However, reordering the logical cpu numbers can further decrease the size of paca_ptrs[] in the kdump case. So I keep [1/3], which rotate-shifts the cpu's sequence number in the device tree to obtain the logical cpu id. Patch [2-3/3] make efforts to decrease the nr_cpus to be less than or equal to two. [1]: https://lore.kernel.org/linuxppc-dev/[email protected]/ Cc: Michael Ellerman <[email protected]> Cc: Nicholas Piggin <[email protected]> Cc: Christophe Leroy <[email protected]> Cc: Mahesh Salgaonkar <[email protected]> Cc: Wen Xiong <[email protected]> Cc: Baoquan He <[email protected]> Cc: Ming Lei <[email protected]> Cc: [email protected] To: [email protected] Pingfan Liu (3): powerpc/setup: Loosen the mapping between cpu logical id and its seq in dt powerpc/setup: Handle the case when boot_cpuid greater than nr_cpus powerpc/setup: alloc extra paca_ptrs to hold boot_cpuid arch/powerpc/kernel/paca.c | 10 +-- arch/powerpc/kernel/prom.c | 26 ++++--- arch/powerpc/kernel/setup-common.c | 106 ++++++++++++++++++++++++----- 3 files changed, 111 insertions(+), 31 deletions(-) -- 2.31.1
